src/swipl-devel/packages/xpce/man/refmanual/md/layout_interface.md

In rswipl: Embed 'SWI'-'Prolog'

class layout_interface {#class-layout_interface}

Abstract interface between a graphical and its layout_manager. A layout_interface holds the per-element geometry hints (row/column position, span, stretch/shrink, alignment, …) that a layout_manager needs to place the element. Graphicals inside a managed device acquire a layout_interface on demand; users normally interact with a concrete subclass (for example a tab_cell) rather than constructing a layout_interface directly.

@see class layout_manager @see class graphical @see class device

Instance variables {#class-layout_interface-instvars}

• layout_interface<-layout_manager: layout_manager* The manager responsible for placing <-image, or @nil if the interface is not currently attached.

• layout_interface<-image: graphical The graphical whose layout this interface controls.

Send methods {#class-layout_interface-send}

• layout_interface->initialise: graphical Bind this abstract interface to the given graphical.

• layout_interface->unlink Detach the interface from <-image, e.g. when the graphical is destroyed.

Get methods {#class-layout_interface-get}

• layout_interface<-convert: graphical -> layout_interface Type-check helper: yield the layout_interface associated with a graphical, creating one on the fly when needed.

rswipl documentation built on June 16, 2026, 5:07 p.m.